This technical specification deals with the steady-state operation of cage induction motors within the scope of IEC 60034-12, when fed from converters. It covers the operation over the whole speed setting range, but does not deal with starting or transient phenomena.<\/p>\n
Only indirect type converters are dealt with. This type comprises converters with impressed direct current in the intermediate circuit (current source converters) and converters with impressed d.c. voltage (voltage source converters), either of the block type or the pulse controlled type, without restriction on pulse number, pulse width or switching frequency. For the purposes of this technical specification, a converter may include any type of electronic switching device, for example transistors (bipolar or MOSfet), IGBTs, thyristors, GTOthyristors, etc. with analog or digital control electronics.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 4<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 5<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | 1 Scope 2 Normative references 3 Characteristics of the motor <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | 4 Frequency spectrum of voltage and\/or currents Figure 1 \u2013 Waveform of phase current iphase in delta connection for current source converter supply (idealized example) <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | Figure 2 \u2013 Waveform of line-to-line voltage uLL for voltage source converter supply with switching frequency fs = 30 x f1 (example) <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | 5 Losses caused by harmonics Figure 3 \u2013 Example for the dependence of the motor losses caused by harmonics Ph, related to the losses Pf1 at operating frequency f1, on the switching frequency fs in case of voltage source converter supply <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | Figure 4 \u2013 Influence of converter supply on the losses of a cage induction motor (frame size 315 M, design N) with rated values of torque and speed <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 6 Torque derating during converter operation Figure 5 \u2013 Fundamental voltage U1 as a function of operating frequency f1 (see clause 6) <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 7 Oscillating torques Figure 6 \u2013 Torque derating factor for cage induction motors of design N, IC 0141 (self-circulating cooling) for current source converter supply as a function of operating frequency f1 (example) <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 8 Magnetically excited noise <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 9 Service life of the insulation system <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | Figure 7 \u2013 Limiting curve of admissible impulse voltage \u00dbLL (including voltage reflection and damping) at the motor terminals as a function of the rise time tr Figure 8 \u2013 Definition of the peak rise time tr of the voltage at the motor terminals <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 10 Bearing currents Figure 9 \u2013 Ring flux including shaft voltage and resulting circulating current icirc <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | Figure 10 \u2013 Common mode circuit model and bearing voltage ubrg <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 11 Installation (cabling, grounding, bonding) 12 Maximum safe operating speed <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 13 Power factor correction <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Rotating electrical machines – Cage induction motors when fed from converters. Application guide<\/b><\/p>\n |